When I was in college, every Tuesday evening at 8:00, my roommate and I would lock our dorm room door, pull down the shades, switch off the lights, and sit with our eyes glued to the television screen watching Cosmos.

Hosted by the late astronomer Carl Sagan, who had a remarkable ability to dazzle his audience with mesmerizing descriptions of the Heavens, Cosmos was instrumental in fueling my love of astronomy.

I wasn't the only one; Sagan's popular books, and his many television talk show appearances, inspired millions of people.

Gifted as both a visionary scientist and a charismatic spokesperson, Sagan was able to share his infectious passion and abundant knowledge with people of all ages and backgrounds.

Although he was best known for being a popularizer of astronomy, Sagan actually spent most of his career as a research scientist at Cornell University.

The author of more than 600 scientific papers, Sagan made some substantial contributions to the field of astronomy.

Sagan helped to determine the scorching temperature on the surface of Venus, (900 °F), and he helped us to better understand the planet's unusual atmosphere.

He also helped to figure out how the seasonal changes on Mars occur, and he was one of the first people to warn us about the dangers of global warming on our own planet.

Sagan was also one of the first astronomers to suggest that Saturn's moon Titan might possess a liquid ocean, and he helped to solve the strange mystery of Titan's reddish haze.

However, the majority of people would probably say that Sagan's most ambitious scientific research was centered around the search for extraterrestrial life.

Sagan demonstrated that the basic building blocks of life--amino acids--can be produced from common chemicals by radiation throughout the universe.

He was also one of the founders of the SETI project. That is, the "Search for Extraterrestrial Intelligence," an organization that uses large radio telescopes to scan the skies for radio signals that might originate from intelligent life elsewhere in the universe.

In 1977, when NASA launched the Voyager Spacecrafts to study the outer solar system and interstellar medium, engineers included 'golden records' onboard, which were created by a committee chaired by Sagan.

Image of the golden records. Credit: NASA

The golden records had instructions engraved on them that were supposedly in universal symbols--such as drawings, sound wave pattern imagery, and binary coding--that, hopefully, an alien intelligence might be able to decipher, and be able to play the records.

When played, on the accompanying phonograph, each golden record contained sounds expressing the cultural diversity of human beings and other life on Earth, including music, sounds of the surf, birds and whale song, along with abundant video images from our world, and data detailing our location in space.

What if these records are discovered by an intelligent alien species some day? Extraterrestrial contact is something that Sagan gave considerable thought to.

The author of more than 20 bestselling science books, perhaps Sagan's most popular book was a science fiction novel called Contact.

The novel--which was made into a motion picture staring Jodie Foster in 1997--is about what might happen if we make contact with an advanced extraterrestrial civilization.

Image: "The Pale Blue Dot" in this image is Earth. At Carl Sagan's request, the Voyager 1 turned its camera towards Earth and captured this image in 1990, when it was 3.7 billion miles from Earth. Credit: NASA

Perhaps, some day, Sagan's dream will be realized, and we'll receive a jaw-dropping reply to our hopeful message on the far-flung Voyager that is, right now some 11 billion miles from our sun, journeying into interstellar space.

Something more to think about when we look up at the Heavens.

David Jay Brown is an award-winning science writer, whose work has appeared in Scientific American, Scientific American Mind, and Discover magazines. He is the author of 12 books about the evolution of consciousness, optimal health, and the future.

What do you think about Carl Sagan's golden records, and passionate search for extraterrestrial intelligence? Tell us in the comments.

Astro-images taken through a telescope on a tracking mount provide breathtaking color and detail that you just can't see with your eyes alone. The astro-images on our web site demonstrate the imaging capabilities of the products used and are not intended to represent what you will see when you look through a telescope.
Learn More

At Orion, we are committed to sharing our knowledge and passion for astronomy and astrophotography with the amateur astronomy community. Visit the Orion Community Center for in-depth information on telescopes, binoculars, and astrophotography. You can find astrophotography "how to" tips and share your best astronomy pictures here. Submit astronomy articles, events, and reviews, and even become a featured Orion customer!